The objective of this project is to survey the patients' environment, and the air, food, water, and products which they utilize in order to detect microorganisms potentially pathogenic for such high risk patients. Patients who carry such pathogens are surveyed to determine if the organisms are being shed into the environment. This study of "shedders" has led to routine isolation of mycosis fungoides patients who carry Staphylococcus aureus. Personnel are surveyed to detect carriers of pathogenic bacteria and procedures are instituted to prevent the spread of these organisms. Effective means of elimination of hazardous organisms are sought. Skin disinfectants were evaluated; as a result, personal preference of 2 effective products is allowed. Foods were examined and methods of decontamination of fresh foods are under study. Decontamination procedures for sink drains are being evaluated. Protective envrionments for high risk patients are also being studied. As a result of intensive efforts to protect the patient, organism acquisition has decreased considerably. Follow-up studies following decontamination procedures to eliminate Aspergillus spores from overheat fire-proofing material revealed very few fungal spores in ambient air.